Various apparatus have been proposed for directing heated pressurized fluid streams, such as air or steam, into the surface of moving textile fabrics to alter the location of or modify the thermal properties of fibers or yarns therein and provide a pattern or visual surface change in such fabrics. Examples of such prior art equipment and methods of application of the pressurized fluid streams to a relatively moving material are disclosed in the following U.S. Pat. Nos.: 2,110,118, 2,241,222, 2,563,259, 3,010,179, 3,256,581, 3,403,862, 3,434,188, 3,585,098, 3,613,186, 3,729,784, 3,774,272.
It is believed that such prior art treatment devices as described in the aforementioned patents, because of the nature of the equipment disclosed, are generally not capable of producing precise, intricate, or well defined patterns of wide variety in the fabrics, but generally can only produce limited or relatively grossly defined patterns, or surface modifications of a random, non-defined nature in the materials. In utilizing high temperature pressurized streams of fluid, such as air, to impart visual surface patterns to textile fabrics containing thermoplastic materials by thermal modification of the same, it can be appreciated that highly precise control of stream pressure, temperature, and velocity is required in all of the individual heated streams striking the fabric to obtain uniformity and preciseness in the resultant pattern formed in the fabric. Where a single continuous stream of substantial width is used, uniformity along the width of the stream is also essential. In addition, there are ever present difficulties in regulating the flow of high temperature fluid streams by use of conventional valving systems to selectively cut the stream flow on or off in accordance with pattern control information.
More recently, apparatus has been developed for more precisely and accurately controlling and directing high temperature streams of pressurized fluid, such as air, against the surface of a relatively moving substrate material, such as a textile fabric containing thermoplastic yarns, to impart intricate patterns and surface changes thereto. Such apparatus, an example of which may be found in commonly assigned U.S. patent application Ser. No. 103,329, filed Dec. 14, 1979, includes an elongate pressurized heated air distributing manifold having a narrow elongate air discharge slot extending across the path of fabric movement in close proximity to the fabric surface. Located within the manifold is a shim plate having a notched edge which resides in the discharge slot to form parallel spaced discharge channels through which the heated pressurized air passes in narrow, precisely defined streams to impinge upon the adjacent surface of the fabric. Flow of the individual heated air streams from the channels is controlled by the use of pressurized cool air which is directed by individual cool air supply tubes communicating with each channel to direct cool air into each discharge channel at a generally right angle to its discharge axis to block the passage of heated air therethrough. Each cool air tube is provided with an individual valve and the valves are selectively cut on and off in response to signal information from a pattern source, such as a computer program, to allow the heated air streams to strike the moving fabric in selected areas and impart a pattern thereto comprised of lines or line segments running in the direction of substrate travel, by thermal modification of the yarns. To maintain more uniform temperature in the individual heated air streams along the full length of the distributing manifold, pressurized air is supplied to the distributing manifold through a bank of individual electric heaters which communicate with the manifold at uniformly spaced locations along its length and are regulated to introduce heated air at the desired temperature along the full length of the manifold.
Although such apparatus as described above provides for highly precise and intricate hot air patterning of substrate materials, the patterns imparted to the substrate are somewhat limited by the configuration of the particular shim plate used. An apparatus using a notched shim plate can only produce a pattern in which the lines or line segments of the pattern correspond to one or more notched locations along the shim plate. For example, if the shim plate has notches 0.04 inch wide on center lines spaced at 0.2 inch intervals, a pattern in which the lines or line segments are spaced across the substrate at 0.2 inch intervals or integral multiples thereof can be produced. But a pattern requiring line segments spaced at, for example, 0.1 or 0.3 inch intervals cannot be produced without replacement of the notched shim plate. If a pattern comprising solid areas, rather than lines or line segments running parallel to the substrate path is desired, the shim plate does not allow pressurized fluid to strike the substrate from any location along the manifold discharge slot which does not correspond to a notch location. This limitation also prevents use of any pattern requiring solid horizontal lines, i.e., lines running perpendicular to the direction of substrate travel. These restrictions severely limit the number and types of patterns which may be used.
Previously referenced U.S. patent application Ser. No. 103,329 discloses a "continuous slit" manifold in which no shim plate is used. In this design, the pressurized cool air used as a blocking means is used to define the discharge channels as well. The heated, pressurized air may be directed onto the substrate from along the entire width of the discharge slot extending across the substrate or from any portion or portions thereof, the full width stream of air being interrupted or blocked only by the flow of pressurized cool air from cool air tubes similar to those used in the shim-type manifold described above. However, use of the continuous slit manifold as described in the above-referenced application sometimes results in unevenly patterned substrates. It has been discovered that the overall design of this continuous slit manifold causes non-uniformities in the flow of heated air from the discharge slot, which in turn, causes non-uniform treatment within the treated areas of the substrate, particularly where the patterns comprise relatively large areas contacted by the heated air, or where the entire width of the substrate, or a substantial portion thereof, is treated.
It is, accordingly, an object of the invention to provide a distributing manifold for heated, pressurized fluids which can direct a continuous stream or blade of heated fluid extending across the width of a moving substrate which results in uniform surface treatment of said substrate.
It is a further object of this invention to provide a distributing manifold for heated, pressurized fluid in which the stream or blade of fluid is substantially uniform with respect to fluid temperature, pressure, and velocity across the full width of said manifold.
It is yet another object of this invention to provide a distributing manifold for heated, pressurized fluids which facilitates economical construction, rapid pattern changes, and routine maintenance.
Other objects and advantages of this invention will become apparent following an understanding of the description and discussion of the invention as presented hereinbelow.